Update gammu.c

Added support for parameters that contain space (or spaces) in batch mode.

For example let's try to send mail in batch mode:
>gammu batch
>sendsms TEXT +48333444555 -text 'Batch mode. Sending sms nr 1'

By default Gammu doesn't work. We'll get following error message: Unknown parameter "mode".
Gammu doesn't care about params written with using " or ' char by default.

My patch fix it.
added variable declaration
Merge pull request #17 from adam-pl/patch-1

Update gammu.c